The present invention relates to a semiconductor device which provides a technique applicable, for example, to power devices.
In the power devices, a lateral reduced surface field (RESURF) transistor is sometimes used as described, for example, in Japanese Unexamined Patent Application Publication No. 2012-39029. Such transistor has a field oxide film between a drain region and a source region. In the transistor described above, a high voltage is applied between the drain region and the source region. The field oxide film is provided for improving a withstand voltage between the drain region and the source region.
Japanese Unexamined Patent Application Publication No. 2010-16153 describes an LDMOS (Laterally-Diffused Metal Oxide Semiconductor) as the power device. In Japanese Unexamined Patent Application Publication No. 2010-16153, LDMOS and CMOS (Complementary MOS) are hybridized over an identical semiconductor substrate.
Japanese Unexamined Patent Application Publication No. Hei07(1995)-263547 describes that a PSG (Phospho Silicate Glass) film and a silicon nitride film are stacked in this order over an aluminum interconnect.